Valve-operating mechanism



July 2, 1929. I c, um N 1,719,737

VALVE OPERATING MECHANISM Filed June 29, 1927 Patented July 2, 1929.

UNITED STATES JOHN C. TURVENE, F DAYTON, OHIO.

VALVE-OPERATING MECHANISM.

Application filed June 29,

This invention relates to improvements in valve operating mechanism for internal combustion motors, the improvements consist ing in a further development of the valve operating mechanism set forth in my copending application for patent Serial No. 158,481, filed January 3, 19 7.

In the accompanying drawings which serve for illustrating the invention: 7

Fig. 1 is a view in sectional elevation of the improved mechanism;

Fig. 2 is a detail sectional view corresponding to Fig. 1 showing the parts in changed relation;

Fig. 3 is a detail sectional view illustra ing corresponding parts of ordinary valve operating mechanism.

The invention as here shown applies in principle to either L-head or valve-in-head types of motors, the invention being here shown and described as applied to L-head mo.- tors.

The object attained in the invention set forth in my copending application for patent consists in effecting quiet operating relation between the valve operating cams and tappets. The objects attained in the further development of the invention as herein shown and described consist in effecting easement of the valve opening and closing actions and quiet seating of the valve.

In the later improvements a condition of operation is attained which approximates mathematically, or theoretically, correct valve action, as given by recognized authorities, the operating spring stress being made to balance the inertia of the high speed of o iieration, and relatively low and theoretically correct valve seating stress being mamtained, which is about 11 pounds pressure per square inch of valve head area.

The drawing, as here shown, includes a detail of the motor cylinder 1, piston 2 and valve housing 3 which is provided with a bearing sleeve 4 for the valve stem 5, and a sleeve 6 for the tappet stem. 7', these parts agreeing substantially with the usual construction of valve mechanism of this character.

The valve stem has a sleeve 8 supported on its lower end by a split ring 9, the sleeve being slidable on the valve stem and having a head 10 which serves as the lower seat for a compression spring 11 confined in a housing 12, and for effecting contact with thetappet in the operation of the mechanism. The up- 1927. Serial No. 202,306

per end of housing 12 is slidable on sleeve 8 and serves as the seat for the opposite end of spring 11. An annular flange 13 of part 12 serves as the lower seat for the primary valve spring which, as here shown, is in two sections 14--15, the upper end of spring 14 be mg seated against the valve housing. A second annular flange 16 of part 12 serves for effecting constant contact with the tappet head 17 which is threaded into the tappet stem 7, being adapted to be retained as adjusted by a lock nut 17. p

A second spring housing 18 is supported slidably on the upper end of sleeve 8 and serves for supporting a compression spring 19 interposed between the lower end of the housing and an annular seat 20 retained onthe sleeve by the outward turned edge 21 of the upper end of the sleeve. The housing 18 has an annular flange 22 which serves for supporting the housing between sections 14 15 of the primary valve spring.

As illustrated in Fig. 1, the lower ends of the valve stem 5 and sleeve 8, when the valve is closed, are spacedfrom .003 to .006 from the tappet head 17 to compensate for expansion and contraction of the metal at variable temperatures of the motor, the spacing of the end of the valve stem being slightly less than that of the sleeve for maintaining contact under spring pressure between the sleeve and its retaining ring 9. Opposite slots 23 are provided in the lower edge of part 12 to permit of inserting a feeler gauge for regulating the air gap 24 by adjusting the tappet head 17. i

For the purpose of illustrating the invention, the tension of spring 14, whenthe valve is closed, is given as (S2pounds, of spring 19, 13 pounds, of spring 15, 75 pounds, being equal to the tension of spring 14 plus that 1 of spring 19, and of spring 11, 56 pounds, which, less the tension of spring 19, or 43 pounds, is exerted on the valve stem, the dif terence in tension between springs 11-15, 19 pounds, being transmitted across the air gap 011 the tappet. The relative spring pressures, as here given, approximate practical working conditions of the valve.

Two combinations of spring stresses exist in the organization and operation of the mechanism, first, that of springs 14-15 and, second, that of springs 11-45-19, spring 15 being common to both combinations, and springs 1115 being under the initial stress of both springs 14-19. Springs 1415 in 7 series exert pressure on the tappet, and spring 111415 in series exert pressureon thevalve stem, the pressure of springs 1415 being divided between the tappet and the valve stem, the greater portion being on'the valve stem. Spring 19 is in oppositionto spring 11 through spring 15. Springs 1119 both be- A 14 becomes equal to that of spring 15, from which point springs 1415 act as one spring, spring 19, in the further opening movement, having decreasing stress due to the compression of spring 15 and the relative greater movement of the valve stem to that of spring housing- 18.

During the closingv movement of the valve, springs 14-15 function as one spring, their compression decreasing and that of spring 19 increasing until the point is reached where the stress of spring 15 becomes greater than that of spring 14,'when spring 14 will control the remaining portion of the closing movement. The valvestem being under the direct influence of springs 11'-19,"and indirectly under the influence of springs 1415, the tappet under the direct influence of springs 14.15, and spring ,11 under less effective stress than spring 14, spring 14 will control the closingimovement of the valve just becal fore and at the instant of seating of the valve stem. .Spring 19 havinga gradually increasing, opposing stress to spring 15 produces a retarding affect on the, closing movement of the valve and aets to change the speed of the closingmovement from that imparted by springs 14-15 acting as one spring to the lower speed of spring 14.- a

-. The action of springs 14-445 is further explained as follows: Graphically speaking relative to the action of coiled compression springs, each turn of the coil exerts the same amount of stress inthe same distance moved. Therefore, considering springs '1415 as one spring having seven, active turnsfive in spring 15 and twoin spring '14the end turns not being considered, the lower end of spring 14 being two turns. away from its upper seat, will move two-sevenths (2/7) of the total distance of expansion of springs 14-15 and in the same time as the total expansion. Thus by efiectin'g the seating connection of the valve, by means of the housing 18,-two'turns away from the upper seat of spring 14, the movement of the second turn of spring 14 is imparted to the spring seat 18 which is only two-sevenths (2/7) asfast as that of the lower end of spring 15, which acts, under the retarding influence of spring 19, to materially reduce the speed of the valve.

Assuming the total combined movements of springs 1415, and of the valve stem, to be 5/16, which approximates practical working conditions, the movement of spring 14 and housing 18 will be only two-sevenths (2/7) of the movement of the valve stem. Thus in the opening movement of the valve, the relative movements of the valve stem and housing 18 are in the ratio of 7 to 2 which results in decreasing the stress of spring 11).

In the closing action of the valve the relative movements of the valve stem and housing 18 are also in the ratio of 7 to 2 which acts to increase the stress of spring 19 and to retard the movement of the valve stem suiiiciently to cause the stem to be lifted oil the tappet as the mechanism approaches the end of the cl osing movement. At the instant when the tappet reaches the lowest point of its movement the valve will be not quite seated, the valve stem being off the tappet, as illustrated in Fig. 3, a distance slightly greater than the normal air gap, the seating of the valve be ing effected, after springs 14 15 have fully expanded and the tappet has reached its dwell between the closing and opening movements of the valve, by the action of spring 11 opposed by spring 19 which has the effect of reducing the force of the valve stem as it engages its seat and, practically, to eliminate the sound of the impact, thus producing the quiet action of the mechanism attained in the invention.

Having described my invention, I claim 1. Valve operating mechanism including in combination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, a primary spring opposed to the actuator, a secondary spring opposed to the primary spring and acting to exert closing pressure on the valve stem, and a secondary spring opposed to the first named secondary spring and adding to the tension of the primary spring as the valve is closed.

2; Valve operating mechanism including in combination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, a primary spring opposed to the actuator, a secondary spring opposed to the primary spring and acting to exert closing pressure on the valve stem, and a secondary spring seated 011 the primary spring and opposed to the first named secondary spring as the valve is closed.

3. Valve operating mechanism including in combination, a valve stem operable axiallv for opening and closing the valve, an actualtor for the valve stem, a primary springopposed to the actuator, a secondary spring opposed to the primary spring and acting to exert closing pressure on the valve stem, and a secondary. spring seated, on the primary spring intermediate the endsthereof and opposed to the first named secondary spring as the valve is closed. a

4. Valve operating mechanism including in con'ibination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, at primary spring opposed to the actuator, a secondary spring opposed to the primary spring and acting to exert closingpressure on the valve stem, and a secondary spring seated on and movable with the prin'iary spring intermediate the ends thereof and opposed to the first named secondary spring.

5. Valve operating mechanism including in combination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, a sectional primary spring opposed to the actuator, a secondary spring opposed to the primary spring acting to exert downward pressure on the valve stem, and a secondary spring seated between sections of the primary spring and opposed tothe first named secondary spring as the valve is closed.

6. Valve operating mechanism including in combination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, a sectional primary spring opposed to the actuator, a secondary spring opposed to the primary spring acting to exert downward pressure on the valve stem, and a secondary spring seated between. sections of the primary spring opposed to the first named secondary spring and acting to decrease and increase respectively the tension of upper and lower sections of the primary spring as the valve is closed.

7. Valve operz'iting mechanism including in combination, a valve stem operable axially for openin and closing the valve, an actuator For the valve stem, a primary spring opposed to the actuator, a secondary spring of less tension than the primary spring, opposed thereto and acting to exert downward pres sure on the valve stem, and a secondary spring of less tension than and opposed to the first named secondary spring, and acting to increase the tension. of the primary spring as the valve is closed.

8. Valve operating mechanism including in con'ibination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, a sleeve seated on the lower end of the valve stem and adapted to be engaged by said actuator, a spring housing slidable on the lower end of said sleeve in constant engagement with said actuator, a primary spring acting against said housing opposed to said actuator, a spring within the housing acting against the lower end of said sleeve opposed to the primary spring and exerting downward pressure on the valve stem, a spring housing seated on the primary spring and slidable on the upper end of said sleeve, and a spring within the upper housing acting against the upper end of the sleeve in opposition to the spring in the lower housing.

9. Valve operating mechanism including in combination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, a sleeve seated on the lower end of the valve stem and adapted to be engaged by the actuator, a spring housing slid able on the lower end of said sleeve in constant engagement with said actuator, a sectional primary spring acting against said housing opposed to the actuator, a spring within the housing acting against the lower end of said sleeve in opposition to the primary spring and exertingdownward pres sure on. the valve stem, a spring housing seated bet-ween sections of the primary spring and slidable on the upper end of said sleeve,

and a spring within the upper housing acting against the upper end of the sleeve in opposition to the spring in the lower housin 10. Valve operating mechanism including in combination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, a sleeve seated on the lower end of the valve stem and adapted to be engaged by the actuator, a spring housing slidable on the lower end of the sleeve in constant engagement with the actuator, a primary spring composed of coacting sections of unequal spring tension, as the valve is closed, acting against said housing opposed to the actuator, a spring within the housing acting against the lower end of said sleeve in opposition to the primary spring and exerting downward pressure on the valve stem, a spring housing seated between the sections of the primary spring and slidable on the upper end of said sleeve, and a spring within the upper housing acting against the upper end of the sleeve in opposition to the spring in the lower housing.

11. Valve operating mechanism including in combination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem, a primary spring opposed to the actuator, a secondary spring opposed to the primary spring acting to exert downward pressure on the valve stem, and a secondary spring opposed to the first named secondary spring, acting to increase the tension of the primary spring, as the valve is closed, and decreasing in tension as the valve stem is actuated for opening the valve and increasing in tension in the closing movement of the valve.

12. Valve operating mechanism including in combination, a valve stem operable axially for opening and closing the valve, an actuator for the valve stem slightly out of direct engagement therewith, as the valve is closed, a primary spring exerting constant pressure on said actuator, and first and second secondary springs opposed one to the other and coacting with the primary spring for reducing pressure on the valve stem, said spring pressures changing relatively one to another in the opening movement of the valve and reverting to normal relation at the instant of seating of the valve.

opening movement and reverting to normal relation in the closing movement of the valve.

14. The herein described method of operating valves consisting in causing primary resistance to the actuating movement of said valve, in causing secondary resistance to the primary resistance and in causing resistance to the secondary resistance for efi'ecting retardation of the movement in the closing action of the valve.

15. The herein described method of operating valves consisting in causing primary resistance to the actuating movement of said valve, in causing secondary resistance to the primary resistance for reducing the primary resistance in the closed relation of the valve.

In testimony whereof, I have aflixed my signature.

JOHN C. TURVENE. 

